Image sensor and electronic device including the same

ABSTRACT

An image sensor includes a semiconductor substrate integrated with at least one first photo-sensing device sensing light in a first wavelength region and at least one second photo-sensing device sensing light in a second wavelength region shorter than the first wavelength region, a photoelectric device including a pair of electrodes facing each other and a light absorption layer between the electrodes, the photoelectric device selectively absorbing light in a third wavelength region between the first wavelength region and the second wavelength region, and a nanostructural body between the semiconductor substrate and the photoelectric device, the nanostructural body including at least two parts having different optical paths.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2013-0093281 filed in the Korean IntellectualProperty Office on Aug. 6, 2013, the entire contents of which areincorporated herein by reference.

BACKGROUND

1. Field

Example embodiments are related to an image sensor and an electronicdevice including the same.

2. Description of the Related Art

A photoelectric device converts light into an electrical signal usingphotoelectric effects, and may include a photodiode and/or aphototransistor, and may be applied to an image sensor and/or a solarcell.

An image sensor including a photodiode requires high resolution and thusa small pixel. At present, a silicon photodiode is widely used, but itmay have a deteriorated sensitivity because it has a small absorptionarea due to small pixels.

On the other hand, a color filter may be used for selectively absorbinglight in a predetermined or given wavelength region in each pixel whenlight enters an image sensor. A red filter, a blue filter, and a greenfilter are respectively disposed on a red pixel, a blue pixel, and agreen pixel and selectively absorb red, blue, and green light, and theselectively absorbed light may be transferred to a photodiode of eachpixel.

However, because the color filter absorbs light by itself, a substantialamount of light is lost while being transferred to the photodiode, andthe area absorbing light in each pixel is decreased to about ⅓ whenincluding, for example, a red pixel, a blue pixel, and a green pixel, sothat each pixel uses only about ⅓ of available light.

SUMMARY

Example embodiments provide an image sensor with improved sensitivityand optical efficiency by enhancing wavelength selectivity for eachpixel while increasing the area absorbing light.

Example embodiments also provide an electronic device including theimage sensor.

According to example embodiments, an image sensor may include asemiconductor substrate integrated with at least one first photo-sensingdevice sensing light in a first wavelength region and at least onesecond photo-sensing device sensing light in a second wavelength regionshorter than the first wavelength region, a photoelectric deviceincluding a pair of electrodes facing each other and a light absorptionlayer between the electrodes, the photoelectric device selectivelyabsorbing light in a third wavelength region between the firstwavelength region and the second wavelength region, and a nanostructuralbody between the semiconductor substrate and the photoelectric device,the nanostructural body including at least two parts having differentoptical paths.

The first wavelength region may be a red wavelength region, the secondwavelength region may be a blue wavelength region, and the thirdwavelength region may be a green wavelength region. The nanostructuralbody may be between the at least one first photo-sensing device and theat least one second photo-sensing device. The nanostructural body mayhave an asymmetric structure. The nanostructural body may include afirst part having a first length along a vertical direction and a secondpart having a second length shorter than the first length. The firstpart may be adjacent to the at least one first photo-sensing device, andthe second part may be adjacent to the at least one second photo-sensingdevice.

The first part and the second part may be in contact with each other orseparate from each other. The nanostructural body may have a width ofless than or equal to about 1 μm, and the first length of thenanostructural body may be less than or equal to about 2 μm. Thenanostructural body may include one of an oxide, a nitride, a sulfide,and a combination thereof. The nanostructural body may include amaterial having a refractive index of about 1.6 to about 2.6.

The image sensor may further include an insulation layer surrounding thenanostructural body between the semiconductor substrate and thephotoelectric device, wherein the nanostructural body may include amaterial having a higher refractive index than the insulation layer. Theinsulation layer may include a silicon oxide, and the nanostructuralbody may include one of a silicon nitride, a titanium oxide, zincsulfide, and a combination thereof.

The pair of electrodes facing each other may be light-transmittingelectrodes, and the light absorption layer may include a p-typesemiconductor material selectively absorbing light in the thirdwavelength region and an n-type semiconductor material selectivelyabsorbing light in the third wavelength region. The third wavelengthregion may be a green wavelength region.

The at least one first photo-sensing device and the at least one secondphoto-sensing device may be arranged along one direction, and thenanostructural body may be between the at least one first photo-sensingdevice and the at least one second photo-sensing device and has a shapethat is elongated along the one direction. The at least one firstphoto-sensing device and the at least one second photo-sensing devicemay be alternately arranged along one direction, and the nanostructuralbody may be arranged in different directions according to the at leastone first photo-sensing device and the at least one second photo-sensingdevice.

The image sensor may further include a focusing lens configured tocollect light into the nanostructural body by controlling the incidencedirection of the light. The focusing lens may be on the photoelectricdevice. The focusing lens may cover at least one of the at least onefirst photo-sensing device and the at least one second photo-sensingdevice.

According to example embodiments, an electronic device may include theimage sensor of example embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a CMOS image sensor according toexample embodiments,

FIG. 2 is a schematic view showing a principle of the image sensor shownin FIG. 1,

FIG. 3 is a schematic view showing various shapes of a nanostructuralbody applied with an image sensor according to example embodiments,

FIG. 4 to FIG. 7 are schematic views showing examples of image sensorsaccording to example embodiments,

FIG. 8 is a graph showing light transmittance of image sensors accordingto Example 1 and Comparative Example 1 depending upon wavelength,

FIG. 9 is a graph showing light transmittance of an image sensoraccording to Comparative Example 2 depending upon wavelength, and

FIG. 10 is a spectroscopic spectrum showing wavelength selectivity of animage sensor according to Example 1.

DETAILED DESCRIPTION

Example embodiments will hereinafter be described in detail, and may beeasily performed by those who have common knowledge in the related art.However, this disclosure may be embodied in many different forms, and isnot construed as limited to the example embodiments set forth herein.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

It should be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers, and/or sections should not be limited by these terms. Theseterms are only used to distinguish one element, component, region,layer, or section from another region, layer, or section. Thus, a firstelement, component, region, layer, or section discussed below could betermed a second element, component, region, layer, or section withoutdeparting from the teachings of example embodiments.

Spatially relative terms (e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like) may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It should be understood thatthe spatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” may encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

The terminology used herein is for the purpose of describing variousembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of exampleembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, example embodiments should not be construed aslimited to the shapes of regions illustrated herein but are to includedeviations in shapes that result, for example, from manufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, including those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand will not be interpreted in an idealized or overly formal senseunless expressly so defined herein.

Referring to FIG. 1, a CMOS image sensor according to exampleembodiments is described.

FIG. 1 is a cross-sectional view of a CMOS image sensor according toexample embodiments.

Referring to FIG. 1, a CMOS image sensor 100 according to exampleembodiments includes a semiconductor substrate 110, a nanostructuralbody 70, an insulation layer 60, a photoelectric device 30, and afocusing lens 40.

The semiconductor substrate 110 may be a silicon substrate, and isintegrated with the photo-sensing devices 50 a and 50 b and thetransmission transistor (not shown). The photo-sensing devices 50 a and50 b may be, for example, photodiodes. The photo-sensing devices 50 aand 50 b and the transmission transistor may be integrated in eachpixel, and the photo-sensing devices 50 a and 50 b sense light and thesensed information may be transferred by the transmission transistor.

The photo-sensing devices 50 a and 50 b include a first photo-sensingdevice 50 a sensing light in a first wavelength region, which is a longwavelength region, and a second photo-sensing device 50 b sensing lightin a second wavelength region, which is a short wavelength region. Thefirst wavelength region may be, for example, a red wavelength region,and the second wavelength region may be, for example, a blue wavelengthregion.

The first photo-sensing device 50 a and the second photo-sensing device50 b are arranged to be parallel along one direction or may bealternatively arranged.

Metal wires (not shown) and pads (not shown) are formed on thesemiconductor substrate 110. In order to decrease signal delay, themetal wires and pads may be made of a metal having low resistivity, forexample, aluminum (Al), copper (Cu), silver (Ag), and alloys thereof,but are not limited thereto.

Nanostructural bodies 70 are formed at predetermined or given intervalson the semiconductor substrate 110. Each nanostructural body 70 includesat least two parts having different optical paths, wherein the opticalpath refers to a distance through which vertically incident light ispassed in the nanostructural body 70.

The optical path may be changed depending upon a length of thenanostructural body 70 in the vertical direction and a refractive indexof the nanostructural body 70, and may be determined by the length ofthe nanostructural body 70 in the vertical direction under thehypothesis that the nanostructural body 70 has a constant refractiveindex regardless of position.

In other words, the nanostructural body 70 may have an asymmetricstructure, and for example, may have a first part 70 a having a firstlength d1 along a direction perpendicular to the semiconductor substrate110 and a second part 70 b having a second length d2 that is shorterthan the first length d1. The first part 70 a having the first length d1may be disposed at the side of the first photo-sensing device 50 asensing light in a long wavelength region, and the second part 70 bhaving the second length d2 may be disposed at the side of the secondphoto-sensing device 50 b sensing light in a short wavelength region.

The first part 70 a and the second part 70 b of the nanostructural body70 may contact each other or may be separated from each other.

The nanostructural body 70 is disposed between the first photo-sensingdevice 50 a and the second photo-sensing device 50 b, and splits whitelight vertically entered into the whole surface into each wavelengthregion, so that the light in the first wavelength region may betransferred into the first photo-sensing device 50 a and the light inthe second wavelength region may be transferred into the secondphoto-sensing device 50 b. Light in a third wavelength region betweenthe first wavelength region and the second wavelength region ispreliminarily selectively absorbed by a photoelectric device 30described later, so as to not pass through the nanostructural body 70.

The nanostructural body 70 may include a material having a predeterminedor given refractive index, for example, a material having a refractiveindex of about 1.6 to about 2.6. The nanostructural body may include anoxide, a nitride, a sulfide, or a combination thereof, and for examplemay include a silicon oxide, a silicon nitride, a silicon oxynitride, ametal oxide, or a metal sulfide.

FIG. 3 is a schematic view showing various shapes of nanostructural bodyapplied to the image sensor according to example embodiments.

The nanostructural body 70 may include a first part having a firstlength b1 in a length direction and a second part having a second lengthb2 that is shorter than the first length b1. The first part and thesecond part of the nanostructural body 70 may be, for example, stepped,sloped, or a combination thereof, but the shape is not particularlylimited.

For example, b1<2 μm, b2<1 μm, and a>0.7 μm in FIG. 3, but they are notlimited thereto.

The lower insulation layer 60 is formed on the semiconductor substrate110. The insulation layer 60 may include, for example, a lowerinsulation layer 61 and an upper insulation layer 62, and the lowerinsulation layer 61 and the upper insulation layer 62 may be made of thesame or different materials.

The insulation layer 60 may be made of an inorganic insulating material(e.g., a silicon oxide and/or a silicon nitride), a low dielectricconstant (low K) material (e.g., SiC, SiCOH, SiCO, and SiOF), and/or anorganic insulation material having improved planarizationcharacteristics.

The insulation layer 60 surrounds the nanostructural body 70, and thenanostructural body 70 may include a material having a higher refractiveindex than that of the insulation layer 60. When the insulation layer 60includes, for example, a silicon oxide (SiO_(x)), the nanostructuralbody 70 may include, for example, a silicon nitride (SiN_(x) (0<x≦1.5)),a titanium oxide (TiO_(x) (0<x≦2)), zinc sulfide (ZnS), or a combinationthereof.

The photoelectric device 30 is formed on the insulation layer 60. Thephotoelectric device 30 includes a lower electrode 31 and an upperelectrode 32 facing each other, and a light absorption layer 33 disposedbetween the lower electrode 31 and the upper electrode 32.

At least one of the lower electrode 31 and the upper electrode 32 is ananode, and the other is a cathode. The lower electrode 31 and the upperelectrode 32 may be light-transmitting electrodes, and thelight-transmitting electrodes may be made of, for example, a transparentconductor (e.g., indium tin oxide (ITO) or indium zinc oxide (IZO)) ormay be a metal thin layer having a thin thickness of several nanometersto several tens of nanometers or a metal thin layer having a thinthickness of several nanometers to several tens of nanometers doped witha metal oxide.

The light absorption layer 33 may selectively absorb light in a thirdwavelength region between the first wavelength region and the secondwavelength region. For example, when the first wavelength region is ared wavelength region and the second wavelength region is a bluewavelength region, the third wavelength region may be a green wavelengthregion. For example, the light absorption layer 33 may selectivelyabsorb light in a green wavelength region, so only light in wavelengthregions other than the green wavelength region passes through thephotoelectric device 30.

The light absorption layer 33 may include a p-type semiconductormaterial selectively absorbing light in a green wavelength region and ann-type semiconductor material selectively absorbing light in a greenwavelength region, and the p-type semiconductor material and the n-typesemiconductor material may form a pn junction. The light absorptionlayer 33 may selectively absorb light in a green wavelength region togenerate excitons, and then the generated excitons may be separated intoholes and electrons to provide a photoelectric effect.

Each of the p-type semiconductor material and the n-type semiconductormaterial may have a bandgap of, for example, about 2.0 to about 2.5 eV,and the p-type semiconductor material and the n-type semiconductormaterial may have a LUMO difference of, for example, about 0.2 to about0.7 eV.

The p-type semiconductor material may be, for example, quinacridone or aderivative thereof, and the n-type semiconductor material may be, forexample, a cyanovinyl group-containing thiophene derivative, but theyare not limited thereto.

The quinacridone or derivative thereof may be, for example, representedby the following Chemical Formula 1.

In the Chemical Formula 1,

R¹ and R² are each independently hydrogen, a substituted orunsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C6to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroarylgroup, or a combination thereof, and

X¹ and X² are each independently hydrogen or a substituted orunsubstituted C3 to C30 heterocyclic aromatic group.

The thiophene derivative may be, for example, selected from a compoundrepresented by the following Chemical Formulae 2a to 2c.

The light absorption layer 33 may be formed on the entire surface of theimage sensor 100, so light may be absorbed on the entire surface of theimage sensor 100, and thus the light area may be increased to providehigh light-absorption efficiency.

The focusing lens 40 is provided on the photoelectric device 30. Thefocusing lens 40 may collect light into one region by controlling theincidence direction of the light. The one region may be a region wherethe nanostructural body 70 is positioned.

The focusing lens 40 may have a size covering at least one firstphoto-sensing device 50 a and at least one second photo-sensing device50 b.

The light collected in the focusing lens 40 is focused into thenanostructural body 70 having an asymmetric structure positioned betweenthe first photo-sensing device 50 a and the second photo-sensing device50 b, and the focused light changes the progression direction accordingto wavelength while passing through the nanostructural body 70. Thereason why the progression direction is changed according to thewavelength while passing through the nanostructural body 70 is that arefractive index difference causing destructive interference and/orconstructive interference is changed according to the wavelength oflight due to the asymmetry of the nanostructural body 70. Accordingly,for example, light of a first wavelength region, which is a longwavelength region, for example, a red wavelength region, may enter intothe side of the first photo-sensing device 50 a, and, for example, lightof a second wavelength region, which is a short wavelength region, forexample, a blue wavelength region, may enter into the side of the secondphoto-sensing device 50 b.

The focusing lens 40 may have a shape of, for example, a cylinder or ahemisphere, but is not limited thereto.

FIG. 4 to FIG. 7 are schematic views showing various examples of imagesensors according to example embodiments.

The image sensor shown in FIG. 4 has a structure in which a plurality ofred photo-sensing devices (R) and a plurality of blue photo-sensingdevices (B) are arranged along one direction, and the image sensorincludes an elongated nanostructural body 70 disposed through aplurality of red photo-sensing devices (R) and a plurality of bluephoto-sensing devices (B) along one direction and a cylindrical focusinglens 40.

The image sensor shown in FIG. 5 has a structure in which a plurality ofred photo-sensing devices (R) and a plurality of blue photo-sensingdevices (B) are alternately arranged along one direction, and the imagesensor includes nanostructural bodies 70 facing different directionsaccording to the red photo-sensing device (R) and the blue photo-sensingdevice (B) and a cylindrical focusing lens 40.

The image sensor shown in FIG. 6 includes a hemispheric focusing lens 40in the image sensor shown in FIG. 4 or FIG. 5.

While the first part 70 a and the second part 70 b of the nanostructuralbody 70 shown in FIGS. 4 to 6 are contact each other, the first part 70a and the second part 70 b of the nanostructural body 70 shown in FIG. 7are separated from each other.

FIG. 2 is a schematic view showing the principle of the image sensorshown in FIG. 1.

As shown in FIG. 2, when white light (WL) passes through the focusinglens 40, for example, light in the second wavelength region (GL) whichis a green wavelength region is selectively absorbed by thephotoelectric device 30 including a lower electrode 31, a lightabsorption layer 33, and a upper electrode 32, and light in wavelengthregions other than the second wavelength region (GL) is focused into thenanostructural body 70 having an asymmetric structure to split theprogression direction according to wavelength, for example, light in thefirst wavelength region (RL), e.g., a red wavelength region, progressesto the side of the first part 70 a of the nanostructural body 70 toenter the first photo-sensing device 50 a, and for example, light in thethird wavelength region (BL), e.g., a blue wavelength region, progressesto the side of the second part 70 b of the nanostructural body 70 toenter the second photo-sensing device 50 b.

The photoelectric device 30 is formed on the entire surface of the imagesensor to provide the wide light area, so that light in the secondwavelength region may have high light-absorption efficiency.

In addition, light of the first wavelength region (RL) and light of thesecond wavelength region (BL) are separated by the nanostructural body70, and respectively enter into the first photo-sensing device 50 a andthe second photo-sensing device 50 b so an additional color filter isnot required. Accordingly, light loss due to a color filter may beprevented or inhibited.

Further, light including light of the first wavelength region (RL) andlight of the second wavelength region (BL) may enter into the firstphoto-sensing device 50 a and the second photo-sensing device 50 b,respectively, after passing through the nanostructural body 70, so thelight area is increased by two times, compared to the case of using acolor filter, to enhance the light-absorption efficiency to light of thefirst wavelength region (RL) and light of the second wavelength region(BL).

Resultantly, the absorption efficiency may be enhanced in all wavelengthregions including the first wavelength region, the second wavelengthregion, and the third wavelength region so as to increase thesensitivity of an image sensor and to improve the performance of anelectronic device including the image sensor.

The electronic device may include, for example, a mobile phone or adigital camera, but is not limited thereto.

Hereinafter, the present disclosure is illustrated in more detail withreference to examples. However, these are examples, and the presentdisclosure is not limited thereto.

Example 1

An image sensor is supposed under the following simulation conditions,and light transmittance and wavelength selectivity are anticipated.

Simulation Conditions

-   -   Nanostructural body: stepped nanostructural body having a first        width (long width) of 0.32 μm, a second width (short width) of        0.16 μm, a first length (long length) of 1.2 μm, a second length        (short length) of 0.6 μm, a thickness of 2 μm, and a        distance (H) from an upper end of the nanostructural body to the        light detector of 2.6 μm,    -   Focusing lens: Gaussian shape    -   Photoelectric device: ITO 100 nm/N,N-dimethylquinacridone        (Chemical Formula 1a)+dicyanovinyl-terthiophene (Chemical        Formula 2a) (1:1 wt/wt, 70 nm)/aluminum 80 nm

Comparative Example 1

An image sensor is prepared under the same conditions as in Example 1,except for changing the condition that a red filter and a blue filterare used instead of the nanostructure and not including thephotoelectric device.

Comparative Example 2

An image sensor is prepared under the same conditions as in Example 1,except for changing the condition that the nanostructural body has ashape of a symmetrical rectangular parallelepiped (width of 0.28 μm,length of 1.20 μm, thickness of 2.00 μm) and not including thephotoelectric device.

Evaluation 1

The image sensors obtained from Example 1 and Comparative Examples 1 and2 are evaluated for light intensity arriving at the light detector whenirradiating white light to the upper part of the focusing lens by thesimulation.

FIG. 8 is a graph showing light transmittance of image sensors accordingto Example 1 and Comparative Example 1, and FIG. 9 is a graph showinglight transmittance of the image sensor according to Comparative Example2.

Referring to FIG. 8, it is understood that the image sensor according toExample 1 has higher light transmittance than that of the image sensoraccording to Comparative Example 1 at the short wavelength region ofabout 400 nm to about 470 nm and the long wavelength region of about 570nm to about 700 nm. From the results, because the image sensor accordingto Example 1 may reduce the light loss due to the color filter, it isassumed that the light-absorption efficiency is higher than that of theimage sensor according to Comparative Example 1.

In addition, light at about 470 nm to about 570 nm, which is the middlewavelength region, is preliminarily selectively absorbed by thephotoelectric device, so it is understood that the image sensoraccording to Example 1 has higher wavelength selectivity in the regionof about 400 nm to about 470 nm, which is the short wavelength region,and in the region of 570 nm to 700 nm, which is the long wavelengthregion.

On the other hand, referring to FIG. 9, the image sensor according toComparative Example 2 has relatively low light transmittance in the longwavelength region and the short wavelength region, and also senses asubstantial amount of light at about 470 nm to 570 nm, which is themiddle wavelength region, so it is understood that the image sensor haslow wavelength selectivity.

From the results, it is understood that the image sensor according toExample 1 may improve light-absorption efficiency and wavelengthselectivity.

Evaluation 2

The image sensor according to Example 1 is evaluated for wavelengthselectivity.

FIG. 10 is a spectroscopic spectrum showing the wavelength selectivityof image sensor according to Example 1.

Referring to FIG. 10, it is confirmed that the wavelength selectivity ofthe image sensor according to Example 1 is high in the short wavelengthregion ranging from about 400 nm to about 470 nm and in a longwavelength region ranging from about 570 to about 700 nm, and it isassumed to be appropriately used in a pixel of about a 1 μm widthbecause both the short wavelength region and the long wavelength regionare sensed within a narrow width within about 1.5 μm.

While this disclosure has been described in connection with what ispresently considered to be practical example embodiments, it is to beunderstood that the inventive concepts are not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. An image sensor, comprising: a semiconductor substrate integrated with at least one first photo-sensing device sensing light in a first wavelength region and at least one second photo-sensing device sensing light in a second wavelength region shorter than the first wavelength region; a photoelectric device including a pair of electrodes facing each other and a light absorption layer between the electrodes, the photoelectric device selectively absorbing light in a third wavelength region between the first wavelength region and the second wavelength region; and a nanostructural body between the semiconductor substrate and the photoelectric device, the nanostructural body including at least two parts having different optical paths.
 2. The image sensor of claim 1, wherein the first wavelength region is a red wavelength region, the second wavelength region is a blue wavelength region, and the third wavelength region is a green wavelength region.
 3. The image sensor of claim 1, wherein the nanostructural body is between the at least one first photo-sensing device and the at least one second photo-sensing device.
 4. The image sensor of claim 1, wherein the nanostructural body has an asymmetric structure.
 5. The image sensor of claim 1, wherein the nanostructural body includes a first part having a first length along a vertical direction and a second part having a second length shorter than the first length.
 6. The image sensor of claim 5, wherein the first part is adjacent to the at least one first photo-sensing device, and the second part is adjacent to the at least one second photo-sensing device.
 7. The image sensor of claim 5, wherein the first part and the second part are in contact with each other or separate from each other.
 8. The image sensor of claim 5, wherein the nanostructural body has a width of less than or equal to about 1 μm, and the first length of the nanostructural body is less than or equal to about 2 μm.
 9. The image sensor of claim 1, wherein the nanostructural body includes one of an oxide, a nitride, a sulfide, and a combination thereof.
 10. The image sensor of claim 1, wherein the nanostructural body includes a material having a refractive index of about 1.6 to about 2.6.
 11. The image sensor of claim 1, further comprising: an insulation layer surrounding the nanostructural body between the semiconductor substrate and the photoelectric device, wherein the nanostructural body includes a material having a higher refractive index than the insulation layer.
 12. The image sensor of claim 11, wherein the insulation layer includes a silicon oxide, and the nanostructural body includes one of a silicon nitride, a titanium oxide, zinc sulfide, and a combination thereof.
 13. The image sensor of claim 1, wherein the pair of electrodes facing each other are light-transmitting electrodes, and the light absorption layer includes a p-type semiconductor material selectively absorbing light in the third wavelength region and an n-type semiconductor material selectively absorbing light in the third wavelength region.
 14. The image sensor of claim 13, wherein the third wavelength region is a green wavelength region.
 15. The image sensor of claim 1, wherein the at least one first photo-sensing device and the at least one second photo-sensing device are arranged along one direction, and the nanostructural body is between the at least one first photo-sensing device and the at least one second photo-sensing device and has a shape that is elongated along the one direction.
 16. The image sensor of claim 1, wherein the at least one first photo-sensing device and the at least one second photo-sensing device are alternately arranged along one direction, and the nanostructural body is arranged in different directions according to the at least one first photo-sensing device and the at least one second photo-sensing device.
 17. The image sensor of claim 1, further comprising: a focusing lens configured to collect light into the nanostructural body by controlling the incidence direction of the light.
 18. The image sensor of claim 17, wherein the focusing lens is on the photoelectric device.
 19. The image sensor of claim 17, wherein the focusing lens covers at least one of the at least one first photo-sensing device and the at least one second photo-sensing device.
 20. An electronic device comprising the image sensor according to claim
 1. 